The efficiency of photovoltaic panels determines how much of the energy in the form of sunlight can be converted into electricity.
Higher efficiency of solar panels used in a photovoltaic system will translate into higher annual electricity yield. For example, a solar panel with an efficiency of 20% and an area of 1m2 will produce 200 kWh/year under standard test conditions – solar radiation of 1000 W/m2 for 2.74 hours a day.
Typically, photovoltaic panels are exposed to sunlight for longer periods during the day, but the intensity of solar radiation is less than 1000 W/m2. A solar panel will produce more energy on a cloudless day when the sun is high in the sky (summer) and less in cloudy conditions or when the sun is low in the sky (winter) .
Highest efficiency of solar cells – the race is on
The web often features articles with flashy headlines “Scientists have broken a world record,” “New record for photovoltaic cell efficiency,” etc. However, what do they mean for us in practice? Figure 1 shows the record results of photovoltaic cell efficiency.
The cells were divided into categories while taking into account the materials from which they were made, as well as the technologies. As you can see, over the years there has been constant competition from both researchers and large photovoltaic companies. Which categories matter most to us? What is the maximum efficiency of photovoltaic panels available to us?
Record efficiency of 47.6% only under laboratory conditions
Researchers at the Fraunhofer Institute for Solar Energy Systems (ISE) have set a new solar cell efficiency record of 47.6%. Such a high result was achieved with a value equivalent to 665 suns, thanks to improvements in the four-layer anti-reflective coating.
Conventional solar cells made of silicon can only absorb sunlight up to a wavelength of 1,200 nanometers, but Fraunhofer ISE’s record-breaking solar cell (made of gallium indium phosphide (GaInP) and gallium arsenide (AlGaAs), attached to a lower tandem solar cell made of gallium indium phosphide (GaInAsP) and gallium indium arsenide (GaInAs)) managed to extend the range to 1,780 nanometers.
“In our research, we aim to make photovoltaics even more efficient and competitive, because we believe that of all renewable sources it is the most sustainable form of electricity generation,” – added Dr. Frank Dimroth – director of the department responsible for the project .
Solar cell with record 39.5% efficiency under “1-sun” lighting conditions
Researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have created a solar cell with a record 39.5% efficiency under global 1-sun illumination. This is the highest efficiency of a solar cell of any type, measured using standard 1-sun conditions.
“The new cell is more efficient and has a simpler design that could be useful in many new applications, such as space-constrained or low-radiation space applications.” – said Myles Steiner, senior scientist in NREL’s High-Efficiency Crystalline Photovoltaics (PV) Group and principal investigator on the project.
Details of the project’s development are presented in the article “Triple-junction solar cells with 39.5% terrestrial and 34.2% space efficiency enabled by thick quantum well superlattices,” which appeared in the May issue of the journal Joule .
NREL scientists previously set a record in 2020, achieving a 39.2% efficient six-junction solar cell using III-V materials.
The most efficient photovoltaic panels available on the market
The very high efficiency boasts the Longi LR7-72HTH-590M model of the Hi-MO 6 series, with 590 watts of power. The panel is built with p-type and Hybrid Passivated Back Contact (HPBC) technology. This model has an efficiency of 22.8%. 
In 2023, JinkoSolar announced that it was launching the first module to exceed the 23% efficiency bariva. The Tiger Neo model in the best variant is expected to reach an efficiency of 23.23%. The model in question is built with TOPCon n-type cells and will reach a power output of 615W.
Among the many photovoltaic modules available on the market, the most noteworthy are those of the German company Bauer Solartechnik bS-540-144M10HBB-GG model with a power output of 540W. The panels are built with 144 half-cells of n-type silicon in half-cut technology. This design ensures high efficiency even in adverse weather conditions. The efficiency of the module is at 20.9%, but the module is built using bifacial technology, which allows additional electricity production from the underside of the module. The panel has successfully passed fire resistance tests, and has numerous certifications, such as IEC 61215, IEC 61730. The uniqueness of Bauer modules is evidenced by an unprecedented high 30-year product warranty and a 30-year line warranty.